docs: def html_output(self, checkers_html):
          '''
          Renders the HTML output for multiple tests and returns it as a string.
  
          @param checkers_html     List of HTML for single tests as returned by
                                   checker_html_output
          '''
          # Note: This relies on checker_html_output having been called so that
          # self.j2 is initialised
          template = self.j2.get_template('ccheck_wrapper.html.j2')
          return template.render(checkers=checkers_html)